Preparation of high molecular weight alcohols



June 21, 1960 c. L. ALDRIDGE ETAI- ,9

PREPARATION OF HIGH MOLECULAR WEIGHT ALCOHOL-S Filed July 23, 1957 CATALYST Moo/PIER] 3 o T0 DECOBALTER OLEFIN 2 H2+CO Clyde Lee Afdridge Neville Leverne Cull lnveni'ors 2,942,034 PREPARATION OF HIGH MOLECULAR WEIGHT ALCOHOLS Clyde Lee Aldridge, Baton Rouge, and Neville Leverne Cull, Baker, La., assignors to Esso Research and Englneering Company, a corporation of Delaware Filed July 23, 1957, Ser. No. 673,700

9 Claims. (Cl. 260-638) The present invention relates to the preparation of oxygenated organic compounds by the reaction of olefins with hydrogen and carbon monoxide in the presence of a carbonylation catalyst. More specifically, the present invention relates to a novel process for producing high molecular weight alcohols containing two more carbon atoms than twice the number in the olefin feed.

It is well known in the art that oxygenated organic compounds may be synthesized from organic compounds containing olefinic linkages by a reaction with carbon monoxide and hydrogen in the presence of catalyst contates Patent" taining metals of the iron group in a two-stage process in which predominantly aldehydes and minor proportions of ketones and alcohols are formed in a first step in the presence of a carbonylation catalyst comprising metals of the iron group and particularly cobalt, and the products from the first step may then be hydrogenated in a second step to convert the organic carbonyl compounds containing one more carbon atom than the olefinic starting material to the corresponding alcohol. Likewise, it desired, the aldehydes may be converted to the corresponding fatty acids by oxidation. The second stage hydrogenation catalyst may comprise any known reduction catalyst such as metallic supported or unsupported nickel, copper chromite, sulfactive catalysts such as oxides and sulfides of tungsten, nickel and molybdenum and the like.

The carbonylation or Oxo reaction by which name this process is generally known, provides a particularly attractive method of preparing primary alcohols to supply the large market for plasticizers, detergents, solvents and the like. Amenable to the reaction to a greater or less degree are long and short chained olefinic compounds, not only hydrocarbons but most other organic compounds having a carbon-to-carbon olefinic linkage such as unsaturated alcohols, acids, esters and the like. Straight and branch chained olefins such as propylene, butene, pentene, hexene, heptene, styrene, olefin polymers such as diand tri-isobutylene, hexane and heptene dimers, polypropylenes, olefinic fractions from the hydrocarbon synthesis process, thermal or catalytic cracking operations and other sources of hydrocarbon fractions containing such olefins may be used as starting materials depending on the nature of the final product desired. The synthesis gas mixture fed to the first stage may be any desired ratio of H to CO, preferably within the limits of 0.5 to 5 volumes hydrogen per volume of carbon monoxide. The conditions for reacting olefins with the synthesis gases vary somewhat in accordance with the nature of the olefin feed, the reaction being generally conducted at pressures in the range of from about 1500 to 4500 p.s.i.g. and the ratio of synthesis gas to olefin may vary widely; in general, about 2500 to 25,000 cubic feet of H +CO per barrel of olefin feed are employed.

The catalyst for the first stage of the process is preferably employed in the form of an oil-soluble compound of the catalytically active carbonylation metal. Thus there have been employed the salts of the metals such as cobalt 2,942,034 Patented June 21, 1960 and high molecular weight fatty acids such as stearic, oleic, naphthenic, linoleic and the like. Water soluble catalysts, such as cobalt acetate, chloride, and the like, have also been successfully employed. Catalyst concentrations may vary from about 0.05 to 5.0% by weight of the catalyst salt calculated as cobalt based on the olefinic feed. The first stage or carbonylation reaction is generally carried out at temperatures in the range of from about 200 or 250 to 450 F. depending upon the nature of the olefin and other reaction conditions. In general, the lower olefins will react at lower temperatures and react to a greater extent than the high molecular weight olefins. 'Ihe carbonylation reaction is an exothermic one, with a heat release of the same high order of magnitude as in the hydrocarbon synthesis process, about 35 to 50 Kcal./gram-mol olefinic double bond reacted and, therefore, careful temperature control is required in the reaction zone to prevent decomposition of cobalt carbonyl to metallic cobalt and also to prevent formation of secondary reaction products and undesired reactions, such as hydrogenation of the olefin, formation of hydrocarbon synthesis product, and the like.

Versatile as this alcohol synthesis, or 0x0 reaction is in the production of alcohols from olefins, the process in the past has not proved itself adaptable to the preparation in good yields of high molecular weight alcohols. These compounds are of particular importance commercially in the manufacture of detergents and a multitude of other purposes. It has been found that, as the molecular weight of the olefin increases, the conversion. to the aldehyde falls off rapidly and, with olefins above about 12 carbon atoms, reaction rates are too slow and yields too low for a commercially feasible operation. This rate and yield decrease with increasing molecular weight of olefin is particularly evident in the case of highly branched olefins, such as those prepared by polymerizing low molecular weight olefins, i.e., the polymers and copolymers of propylene, butylenes and amylenes.

It is, therefore, a purpose of the present invention to disclose a novel process of producing substantial yields of high molecular weight primary alcohols by the carbonylation reaction.

It is a further purpose of the present invention to produce these high molecular weight dimer alcohols from olefins having a substantially lower molecular weight, which olefins are in considerably larger supply than high molecular weight olefins, without a decrease in total alcohol yield.

Other and further purposes and objects of the present invention will become more apparent hereinafter.

It has hitherto been found that, accompanying the main carbonylation reaction, i.e., the reaction wherein an olefin is converted to an aldehyde having one more carbon atom, there is formed a large number of secondary reaction products, such as esters, aldols, polymers, ketones and the like. It has now been found that, by addition of the reaction modifier of this invention there is formed, in good yields, a primary alcohol product having 2n+2 carbon atoms, where an olefin with n carbon atoms is passed to the carbonylation zone, It being an integer in the range of from 3 to 14. As stated earlier herein, propylene, heptene, styrene, dimers of heptene and the like are typical of olefins suitable for use herein. Accompanying this reaction is the normal aldehyde synthesis reaction producing aldehydes and alcohols having n+1 carbon atoms. Other secondary reaction products are substantially absent; the normal reaction product also is formed to a substantially smaller extent than in the absence of the reaction modifier.

In accordance with the present invention, the high molecular weight alcohols which will be referred to herein as dimer alcohols may thus be produced from low molec- 3 ular weight olefins by the carbonylation reaction, followed by hydrogenation, when the carbonylation stage is conducted in the presence of oil soluble compounds of the elements, of group -IA which ipcludeslithium, sodium, potassium, etc. saltsof fatty acids,e.g. oleic, stearic, n'aphthenic; linoleic. The oil soluble alkali in etal alcoholates such as octyl, d'ecyl, tridecyl, 'lauryhetc, may also be employed. 7 v

The process itself is conventional save for the use of the modifiers mentioned above. These modifiers may be added in either solution or as solids from a pressurized hopper. The manner in which the reaction modifiers are added is not critical. Preferably, however, these will be added to the olefin feed or solvent therefor although they may be injected into the reactor separately at different points. K

In accordance with one embodiment of the present 1nvention, there is passed into the first stage reaction zone,

more detailed description hereinafter, wherein reference will be made to the accompanying drawing which is a schematic illustration of a system suitable for carrying out a preferred embodiment of the invention.

Referring now to the'drawing, an olefinic hydrocarbon is fed through feed line 2 to the bottom of primary reactor 1. The latter comprises a reaction vessel preferably divided into discrete zones separated by trays and free space. The reactor is preferably packed with inert solids to facilitate gas-liquid contact.

Also passed into reactor Ii are cobalt carbonylation catalyst and the oil soluble alkali metal reaction modifier. In a preferred modification, a mixture of cobalt and re action modifier is employed dissolved in the olefin feed and is admitted through line 2.. It is to be understood that other forms of cobalt, such as an aqueous solution or a cobalt salt, i.e., cobalt acetate, or a slurry of oilinsoluble cobalt solids, such as cobalt oxide, metal carbonate andthe like, may be employed. Cobalt is generally added preferably to the extent of 0.1 wt. percent to 0.5 wt. percent or .01 to. .06 mol/liter calculated 'as metal in. olefin feed, while the group IA metal compound is added to the extent of .01. to .2 mole/liter, preferably 002 to .05 mole/ liter calculated as metal in olefin feed.

Simultaneously, a gas mixture containingv H andCO 1 through line 6. The product, which is at a temperatureof about 300 to 375 E, is then passed to cooler i, where the temperaturev is lowered to about 60 to 120 F., and

then passed to high pressure gas-liquid separator 53; Herein separation of unreacted gases from liquid product occurs. The unreacted gases may be withdrawn through line 9, and after scrubbing, may be recycled to the system via line 10, or in part purged. Liquid aldehyde product containing high concentration of cobalt carbonyl is Withdrawn from high pressure separator 8 through line 12. A portion of this stream is preferably passed via line13 to aldehyde synthesis reactor. 1 to supply both cooling and a portion of the catalyst requirements. of that vessel, the amount of product recycled being a function of the amount of cooling required in the reactor. The recycled liquid is preferably added along the length of reactor 1. Qther means for, coolingmay be employed if desired.

Liquid aldehyde product not recycled to reactor 1 is passed through pressure release valve 14 and line 15. This material, containing dissolved cobalt carbonyl and lithium compound is sent to a catalyst decomposition or decobalting zone, where in the presence of heat and steam, Water, or dilute organicacid, the metal contaminants may be removed from the aldehyde product. The metal compounds may be'decornpos'ed by 'indirect'heating',

' steam, etc., or be made insoluble in the organic mixture in the approximate ratio of 0.5 to 2 volumesH' iper'mole by treatment with a low molecular weight organic acid such as acetic, oxalic etc. Various demetallizing tech niques are known and in this invention any one" maybe employed.

The aldehyde product, substantially completely free of inorganic compounds, is then hydrogenated under conventional conditions to alcohols and the alcohol product fractionated to produce both the n+1 and the 2n+2 alcohols, as described. p

The processof the present invention may befurther illustrated by theiollowing speciiic examples;

Example 1 One liter of 0, U0? olefin was oxonated for six hours at 350 F., and 3000 p.s.i.g. of 1.1/1 H /CO gas pressure.

The catalyst consisted of 0.033 mole of cobalt oleate. The

metal additive consisted of 0.022 mole of lithium oleate. The reaction mixture was then freed of cobalt carbonyl by heating to 350 F. under 500 to 1000 p.s.i.g. hydrogen pressure. Hydrogenation of the product was accomplished by treating the decobalted product with 12. vol. percent of reduced nickel catalyst at 3000 p.s.i.g. of CO free hydrogen pressure for 6 hours at 350 F. The product was distilled at 20. mm. pressure, after hydrocarbon was removed at atrn. pressure, ma 1 inch 30 plate Oldershaw column at 5/1 reflux ratio. The product was-found to consist of the, following:

Weight, percent 20 mm. Press.

Initial-265 2651-995 7 225-330 330-360 360+ 0.022 mole of potassium oleate was used instead oflithium oleate. The product consisted of Weight,

: B.R., O F. 7

percent Component 2 mm. Press.

Initial 265 265 -225 22am 330-260 Hydrocarbon 01; Alcohol. I Intermediate C Alr-nhnl Bottoms atmosphencpressure temperature.

Example 3 A run was-made similar to Example 1 except thflfiLOZii mole of sodium stearate was used instead of lithium oleate. The product consisted of:

an, e F. Wt

Component.

20 mm. Press. percent Initial265 Hydrocarbon r 08 Alcohol- Intermediate 0 Al r-nh nl Bottoms 1 Atmosp ericrressurestemneraturei Example Triplicate runs similar to Example 1 were made except that no metal additive was used other than the cobalt. The product consisted of the following:

1 Atmospheric pressure temperature.

These data show the directional effect in the production of C alcohol from C olefins when oil soluble lithium compounds are employed. It will be noted that practically no dimer alcohol yield is obtained when not employing salts of metals of group IA under identical conditions.

Though the invention has shown at length the conversion of heptenes to C alcohols, the invention is not restricted thereto. With higher boiling olefins corresponding higher boiling alcohols are produced, thus affording, for example, economical preparation of C to C24 alcohols.

Dimer alcohols also may be produced by thermally soaking the crude aldehyde product in the presence of the modifiers noted above. Typical conditions which may be employed for the thermal soaking are 0.05-5 wt. percent of modifier for 2-48 hours at 200-450 F. and at atmospheric conditions to 1000 p.s.i.g. Preferably, the modifier employed should be soluble in the oxygenated product. The most outstanding results are achieved by contacting or thermally soaking the aldehyde product in the presence of the aforesaid modifiers prior to the decobalting operation. There is apparently some co-action between the cobalt catalyst and the modifier which effects good yields of the desired dimer product. The following is an example of the thermal soaking technique.

Example 5 One liter of C UOP olefin is oxonated for 6 hours at 350 F. and 3000 p.s.i.g. with H;/C0 gas pressure ratio of 1:1. The cobalt-containing catalyst comprises 0.033 mole of cobalt oleate. The reaction product is then passed to a thermal soaking drum wherein a 0.5 wt. percent of lithium oleate calculated as lithium on the oxygenated product is added and the mixture maintained at 350 F. for 6 hours. The resulting product will contain substantial amounts of dimer aldehyde. Demetallizing and hydrogenation is carried out as noted .in Example 1 to produce the C alcohol. Advantageously, if the thermal soaking is carried out prior to decobalting, the cobalt and metal modifier may be removed in a single step.

What is claimed is:

-1. The process for converting an olefinic compound having 12 carbon atoms in the molecule into primary alcohols having 2n+2 carbon atoms, n being an integer in the range of from 3 to 14, which comprises passing said olefinic compound, H;,, CO, a cobalt carbonylation catalyst, and a modifier comprising an alkali metal salt of a higher fatty acid into a carbonylation zone, said modifier being employed in an amount of from 0.01 to 0.2 mole per liter on olefinic compound calculated as metal, maintaining carbonylation temperatures of from about 200 to 450 F. and pressures of from about 1500 to 4500 p.s.i.g. in said zone, withdrawing an aldehyde product from said zone, hydrogenating said product, and recovering a primary alcohol having 2n+2 carbon atoms.

2. The process of claim 1 wherein said modifier is an oil soluble lithium salt of a higher fatty acid.

3. The process of claim 1 wherein said modifier is an oil soluble potassium salt of a higher fatty acid.

4. The process-of claim 1 wherein said modifier is an oil soluble sodium salt of a higher fatty acid.

5. An improved process for producing primary monohydric alcohols having 2n+2 carbon atoms from olefins having n carbon atoms, n being an integer in the range of from 3 to 14, which comprises passing said olefins, H CO, a cobalt carbonylation catalyst and a reaction modifier comprising an oil soluble alkali metal salt of a higher fatty acid into a carbonylation zone, said salt being added in an amount of from 0.01 to 0.2 mole per liter on olefin calculated as metal, maintaining temperature of from about 250-450 F. and pressures of from about 1500-4500 p.s.i.g. in said zone, withdrawing an aldehyde comprising reaction product from said zone, removing metal-comprising components from said reaction product, hydrogenating said aldehyde product and recovering said primary alcohol product.

6. The process of claim 5 wherein said alkali metal salt is a lithium salt. 7

7. The process of claim 5 wherein said alkali metal salt is a potassium salt.

8. The process of claim 5 wherein said alkali metal salt is a sodium salt.

9. The process of converting heptenes into primary isohexadecyl alcohols which comprises passing a heptene fraction into a carbonylation reaction zone, passing H CO and 0.05-0.5% cobalt oleate, calculated as cobalt on olefin, into said zone, passing .01 to .2 mole/liter of a group IA metal salt of a higher fatty acid into said zone, said salt being dissolved in said heptene fraction, maintaining temperatures of from about 250-375 F. and pressures of from 1500-4500 p.s.i.g. in said zone, withdrawing an aldehyde comprising reacting product, freeing said product of dissolved and suspended cobalt and metal components, hydrogenating said aldehyde product, and recovering a primary isohexadecyl monohydric alcohol product.

Wender et al.: Report of Investigations 4270, Bur. of Mines, Dept. of Interior, June 1948, pp. 8-11. 

1. THE PROCESS FOR CONVERTING AN OLEFINIC COMPOUND HAVING N CARBON ATOMS IN THE MOLECULE INTO PRIMARY ALCOHOLS HAVING 2N+2 CARBON ATOMS, N BEING AN INTEGER IN THE RANGE OF FROM 3 TO 14, WHICH COMPRISES PASSING SAID OLEFINIC COMPOUND, H2, CO, A COBALT CARBONYLATION CATALYST, AND A MODIFIER COMPRISING AN ALKALI METAL SALT OF A HIGHER FATTY ACID INTO A CARBONYLATION ZONE, SAID MODIFIER BEING EMPLOYED IN AN AMOUNT OF FROM 0.01 TO 0.02 MOLE PER LITER ON OLEFINIC COMPOUND CALCULATED AS METAL, MAINTAINING CARBONYLATION TEMPERATURES OF FROM ABOUT 200* TO 450*F. AND PRESSURES OF FROM ABOUT 1500 TO 4500 P.S.I.G. IN SAID ZONE, WITHDRAWING AN ALDEHYDE PRODUCT FROM SAID ZONE, HYDROGENATING SAID PRODUCT, AND RECOVERING A PRIMARY ALCOHOL HAVING 2N+2 CARBON ATOMS. 